1. Field of the Invention:
The present invention relates broadly to multilayer, onepiece, disposable diapers, and more particularly to diapers of the above type in which an absorbent pad is independently movable relative to a backing layer.
2. Description of the Prior Art:
Disposable diapers have become exceedingly popular in recent years. Commercially, the most successful disposable diapers have been of a multilayer, one-piece construction including a facing layer which is pervious to body fluids, an intermediate fluid-absorbing core for absorbing and retaining body fluids which pass through the facing layer and a liquid-impervious backing layer beneath the absorbent core for preventing body fluids from striking through the diaper. In these multilayer constructions the facing layer generally is intimately adhered to the backing layer at the side and end margins, and such intimate adherence prevents any significant relative movement between the various diaper components during use. In use the forces imposed upon these diapers in the thigh and waist encircling regions of a wearer are readily transmitted to the absorbent core through both the facing and backing layers. These forces can cause the absorbent core to shift out of desired conformation with the perineal region of the wearer to adversely affect the fluid-retaining capabilities of the diaper. Furthermore, due to the intimate adherence of the facing and backing layers at the side and end margins thereof the components of the diaper cannot easily be separated from each other. Separation of the diaper components is often desirable to permit disposal of flushable components in a conventional household toilet system.
The above-referred-to prior art diapers are not designed to permit manipulation of the absorbent core independently of the backing layer. Manipulation of the absorbent core may be desired to permit varying its geometry within the perenial region for accommodating the excretion characteristics of the wearer. For example, the excretion characteristics may vary with the age and sex of the wearer.
Representative multilayer, one-piece, disposable diapers which are subject to the above-described deficiencies are disclosed in U.S. Pat. Nos. Re. 26,151, issued to Duncan et al; 3,885,568, issued to Schaar; 3,816,227, issued to Schaar; 3,402,715, issued to Liloia et al; 2,788,786, issued to Dexter; 3,509,881, issued to Sabee and 2,788,003, issued to Morin.
U.S. Pat. No. 2,507,197, issued to Matzdorf, discloses a multilayer, one-piece diaper in which the absorbent material is in the form of separate fibrous layers that are intimately adhered to a backing layer through a liquid-impervious barrier sheet. This diaper does not permit manipulation of the absorbent layers independently of the backing layer.
Two-piece diaper systems have also been suggested in the prior art. These systems include a retaining garment which generally is adapted to be used over an extended period of time, and an absorbent pad which is removably secured to the retaining garment during use of the diaper. These two-piece diaper systems, in some cases, permit independent manipulation of the absorbent pad relative to the retaining garment. Also, forces imposed upon the retaining garment in regions encircling the thigh and waist regions of a wearer are not transmitted as readily to the absorbent pad as is the case with the above-described multilayer, one-piece diaper system.
The absorbent pads and retaining garments of the two-piece diaper systems are generally sold separately. This method of merchandising requires stores to stock various sizes of pads and various sizes of retaining garments. It has been found that an out-of-stock situation in one of the items generally has an adverse effect on the total volume sales of the entire diaper system. Accordingly, the two-piece diaper systems are considerably more difficult to successfully merchandise than the conventional multilayer, one-piece disposable diapers. Moreover, the retaining garments of the two-piece diaper systems have generally been highly durable due to the fact that they are intended to be utilized over an extended period of time. These highly durable retaining garments have been relatively expensive to manufacture, and therefore, the two-piece diaper systems employing such retaining garments do not easily compete in the low cost disposable diaper market. The diaper disclosed in U.S. Pat. No. 3,693,621, issued to Jarusik et al, is representative of the above-described two-piece diaper sytems.
It has also been suggested to employ separate inserts to be utilized with conventional multilayer, one-piece disposable diapers, as exemplified by the disclosure in U.S. Pat. No. 3,886,941. These inserts are sold separately from the disposable diapers, and are placed on the disposable diaper when needed for added absorbency. Such constructions do not in any way relate to multilayer, one-piece diaper constructions of the type which form the subject matter of the instant invention.
U.S. Pat. No. 3,505,083 discloses a two-ply wrapper for commestible products comprising a moisture absorbent layer selectively adhered at spaced points to a plastic film such that the two components can move relative to each other in the unbonded areas. This patent does not relate to disposable diapers of any type, and accordingly, does not relate to the multilayer, one-piece diaper constructions which form the subject matter of the instant invention.